Catalysed filter
AssigneeJohnson Matthey Public Limited Company
InventorDavid William Prest
Life of this patent
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Abstract
A wall-flow filter monolith substrate having a porosity of at least 40% formed from a selective catalytic reduction (SCR) catalyst of extruded type.
Claims10
A wall-flow filter monolith substrate comprising an extruded selective catalytic reduction (SCR) material, wherein the material comprises a zeolite containing at least one transition metal and wherein said substrate has a porosity of at least 40%.
(canceled)
A method for making a wall-flow filter monolith substrate comprising forming an extruded flow-through monolith substrate comprising a selective catalytic reduction catalyst and having an array of flow channels including first and second open channel ends, which flow-though monolith substrate having, or is capable of having, a porosity of at least 40%, inserting a plug-forming material into a plurality of first channels to form a substantially impermeable plug at the first end of the plurality of first channels and inserting the plug-forming material into a plurality of second channels to form a substantially impermeable plug at the second end of the plurality of second channels, wherein said inserting the plug transforms the flow-through monolith to a wall-flow monolith.
Dependencies are inferred from the claim text.